Geographic information systems provide for the archiving, retrieving, and manipulating of data that has been stored and indexed according to geographic coordinates of its elements. A geographic information system generally includes a variety of data types, including imagery, maps, and tables. Improvements in computer processing power and broadband technology have led to the development of interactive geographic information systems that allow for the navigating and displaying of geographic imagery. Some interactive geographic information systems provide a user interface with navigation controls for navigating cities, neighborhoods, geographic areas and other terrain in two or three dimensions. The navigation controls can enable users to tilt, pan, rotate, zoom, and activate views of terrain, buildings, and other objects from different perspectives at a geographic area of interest. An example of an interactive geographic information system for navigating geographic imagery is the Google Earth™ virtual globe application and the Google Maps™ mapping application developed by Google Inc.
The imagery used by these interactive systems can be derived by rending geometric objects and texture objects to generate a two-dimensional or three-dimensional graphical representation of a geographic area of interest. The geometric objects can define three-dimensional surfaces of objects (e.g. buildings, bridges, etc.) and terrain depicted in the imagery. For instance, in a virtual globe application, the geometric objects can include geometric tiles having a plurality of mesh triangles used to model the terrain and other geometry of a geographic area. Other suitable geometric objects can be used to model objects such as buildings, bridges, and other features. Texture objects can be mapped to the three-dimensional surfaces of the geometric objects to add detail, surface texture, color and other features to the graphical representation. For instance, in a virtual globe application, texture objects based on map imagery, satellite imagery or other geographic imagery can be rendered on terrain surfaces to enhance the graphical representation of the geographic area in the virtual globe application.
Interactive systems for displaying imagery, such as geographic imagery, often render geometric objects, such as terrain objects, with low level of detail (e.g. low resolution) at camera views far from an area of interest to improve performance. As the user zooms in closer to the area of interest, geometric and texture objects with higher level of detail (e.g. higher resolution) are rendered to depict objects in greater detail. Transitioning between two levels of detail can cause a distracting pop if the levels of detail are sufficiently different and/or the transition happens too close to the camera view. The pop can be a visual anomaly which disrupts the user's sense of immersion in the imagery.